Milia was the daughter of unknown parents. The date and place of her birth have not been found.
Her husband was Rodrigo II Romanes de Monterroso. They were married, but the date and place have not been found. Their five known children were Fernando Rodríguez (c0815-?), Roman III Rodríguez (?-?), Remón II Rordíguez (?-?), Gutierre Rodríguez (?-?) and Suero Gallego (?-?).